Well obviously the more the better in any case, so with that said i did 1 plant with 8 23W 2700 K lights and a dual 48 inch fixture with 1 40W 6500K & 1 40 W 3000K. i had 4 lights with the socket splitter so i could have 2 cfls in 1 outlet as im sure you've seen on here. and the plant was growing nice. but it only got 10 days into flowering when i had to plunk it cause it was a DUDE LOO.
You place the cfls 2-3 inches away from plant.(place you hand in front of your bulb to were its warm but not hot and your safe). you'll have to move lights basicly daily so they wont get burn by the lights. in flowering your plant grows like crazy, the first 1-2 weeks of flowering your plant will most likly double in size, depending the strain even quadruple in size thoughout the whole flowering process! but make sure when you buy the bulbs for flowering they are the 2700K. hope this help you out a bit man! pce